I saw this question severall times (e.g. What projection to use to get a game map into QGIS? and How do I specify a CRS for a fictional game map in QGIS?) but since I am new to GIS, I need further instructions.
I am trying to port the map from the game PLAYERUNKNOWN's BATTLEGROUNDS to the right format for a tileserver. My goal is to create an android app which shows the map using some SDK like Google Maps or Mapbox. There already exists an online version from another developer.
So far I used MapTiler to convert an image of the map to map tiles. However, when I use "Standard Tiles", the map is projected on a globe an therefore the image is stretched and clinched. Using the option "Raster Tiles" creates some white borders around my map and I think makes it harder to add POIs later, because I don't have a coordinate system.
Can anyone tell me how to convert this image of the map into a GIS format while still preserving the coordinate system from the game so that I can later add POIs (spawn locations for vehicles and items) on the map using the same coordinates as in the game?
For reference: The distance between two white lines on the linked map is 100m and the distance between two yellow lines is 1km.
I am an experienced android developer but this projections and coordinates stuff is very confusing for an outsider.